Lipids

• Lipids are nonpolar and, therefore, hydrophobic
• Lipids can directly bypass through cellular membrane
• Saturated fatty acids have only single C-C bonds
• Unsaturated fatty acids contain one or more C=C double bonds
• 1 mol of fatty acids oxidized produced up to 9kcal of energy
• Saturated fatty acids store more energy than unsaturated ones
• Saturated fatty acids are solid in room temperature
• Unsaturated fatty acids are liquid in room temperature
• This is a saturated fatty acid

  
• This is unsaturated fatty acid

  
• This is a structure of triglyceride

  
• This is a structure of glycerol

  
• This is a phosphoglyceride

  
• Phospholipids are part of cellular membrane because they are amphipathic
• In phosphoglycerides, phospate group faces outside and inside of membrane and fatty acids are within the membrane
• Glycolipids are composed of glycerol with attached to it fatty acids and carbohydrate
• Sphingolipids have a backbone made of sphingosine with attached to it fatty acid and polar head group (could be a phosphate)
• Glycolipids are found in abudance in membranes of myelinated cells
• Important steroids for MCAT are some hormones, vitamin D and cholesterol
• Cholesterol is important for membrane stability and fluidity
• Terpenes are lipids and they include vitamin A
• Eicosanoids are local hormones released from cell membrane and they include prostaglandins
• Lipids travel in blood via lipoproteins which are made of phospholipids and apoproteins
• Lipoproteins are classified by their density: the higher the density, the more proteins
• HDL has more proteins than lipids (abbreviation only)
• VLDL has more lipids than proteins (abbreviation only)
• Isoprene is the smallest unit of terpenes
• To get MONOterpen, you need 2 isoporene units
• Single tailed phospholipids form micelles
• Glycolipids are involved in cell recognition
• Apoproteins in lipoproteins are amphipathic
• Chylomicrons are the largest and have the highest lipid content among all lipoproteins
• HDL removes excess cholesterol from cells and transports it back to liver